Invasive Staphylococcus aureus Infection Tracking


Staphylococcus aureus is a leading cause of healthcare-associated infections in the United States and an important cause of serious infections in the community. Methicillin-resistant S. aureus (MRSA) is one of the most important antibiotic resistant bacteria in the United States. Data from this project will inform policy and prevention strategies to reduce S. aureus infections, including MRSA.

The Emerging Infections Program (EIP) invasive S. aureus infection surveillance program was launched in 2004 as a part of EIP Active Bacterial Core surveillance (ABCs). Between 2004 and 2014, surveillance focused only on invasive MRSA infections in 9 EIP sites. In 2016, it officially became a part of the EIP Healthcare-Associated Infections Community Interface (HAIC) and incorporated surveillance for both methicillin-resistant and methicillin-sensitive S. aureus (MSSA). Invasive S. aureus surveillance currently operates in selected counties in 7 EIP sites across the United States and has approximately 16 million people living in the surveillance area.

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Surveillance Objectives

The goals of the surveillance project include:

  • Monitoring changes in incidence of hospital-onset (HO), healthcare-associated community-onset (HACO), and community-associated (CA) invasive S. aureus infections
  • Identifying populations with invasive S. aureus that would benefit from improved prevention and treatment activities,
  • Assessing the impact of established prevention strategies, with a focus on community-onset infections.
  • Describing the molecular and microbiologic characteristics of strains causing invasive S. aureus infections, with a focus on community-onset S. aureus isolates.
Additional Information


Surveillance Population

Surveillance is conducted in seven EIP sites, with surveillance areas for MRSA and MSSA differing in some sites. As of July 2019, the total population under surveillance was 16,005,008, according to the U.S. Census Quick Facts  population estimates accessed August 3, 2020.

Population Under Surveillance
EIP Program Site Area under Surveillance Surveillance Population
California 3 county metropolitan San Francisco Bay area 3,683,771
Connecticut Statewide 3,573,297
Georgia 8 counties in metropolitan Atlanta 4,086,198
Maryland Baltimore City and County 1,439,126
Minnesota 2 counties in metropolitan Minneapolis-St. Paul area 1,792,733
New York 1 County in metropolitan Rochester 742,724
Tennessee 1 County in metropolitan Nashville 687,159
Total Population Surveilled 16,005,008

Case Definition

To be considered a case, the following conditions must both be met:

  • S. aureus isolated from a normally sterile site, such as blood, cerebrospinal fluid (CSF), pleural fluid, peritoneal fluid, pericardial fluid, bone, joint/synovial fluid, or internal body site (e.g., lymph node, brain), and
  • Case patient must be a resident of one of the defined surveillance areas

Data Collection

The invasive S. aureus infection surveillance program is an active population- and laboratory-based surveillance system. Surveillance staff regularly query laboratories for reports of results among patients in a specifically defined geographic area.


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Grigg C, Palms D, Stone ND, Gualandi N, Bamberg W, Dumyati G, Harrison LH, Lynfield R, Nadle J, Petit S, Ray S, Schaffner W, Townes J, See I. Burden of invasive methicillin-resistant Staphylococcus aureus infections in nursing home residents . J Am Geriatr Soc. 2018 Aug 10. doi: 10.1111/jgs.15451.

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Gualandi N, Mu Y, Bamberg W, Dumyati G, Harrison LH, Lesher L, Nadle J, Petit S, Ray SM, Schaffner W, Townes J, McDonald M, See I. Racial disparities in invasive methicillin-resistant Staphylococcus aureus infections, 2005-2014 . Clin Infect Dis. 2018 Apr 5. doi: 10.1093/cid/ciy277.

See I, Wesson P, Gaulandi N, Dumyati G, Harrison LH, Lesher L, Nadle J, Petit S, Reisenauer C, Schaffner W, Tunali A, Mu Y, Ahern J. Socioeconomic Factors Explain Racial Disparities in Invasive Community-associated Methicillin-Resistant Staphylococcus aureus Disease Rates . Clin Infect Dis. 2017 Mar 1;64(5):597-604. doi: 10.1093/cid/ciw808.

Nguyen DB, See I, Gualandi N, Shugart A, Lines C, Bamberg W, Dumyati G, Harrison LH, Lesher L, Nadle J, Petit S, Ray SM, Schaffner W, Townes J, Njord L, Sievert D, Thompson ND, Patel PR. Completeness of MRSA bloodstream infection reporting from outpatient hemodialysis facilities to the national healthcare safety network, 2013 . Infect Control Hosp Epidemiol. 2016 Feb;37(2):205-7. doi: 10.1017/ice.2015.265. Epub 2015 Nov 11.

Epstein L, Mu Y, Belflower R, Scott J, Ray S, Dumyati G, Felsen C, Petit S, Yousey-Hindes K, Nadle J, Pasutti L, Lynfield R, Warnke L, Schaffner W, Leib K, Kallen AJ, Fridkin SK, Lessa FC. Risk Factors for Invasive Methicillin-Resistant Staphylococcus aureus Infection After Recent Discharge From an Acute-Care Hospitalization, 2011-2013 . Clin Infect Dis. 2016 Jan 1;62(1):45-52. doi: 10.1093/cid/civ777. Epub 2015 Sep 3.

Reno J, Doshi S, Tunali AK, Stein B, Farley MM, Ray SM, Jacob JT. Epidemiology of methicillin-resistant Staphylococcus aureus bloodstream coinfection among adults with Candidemia in Atlanta, GA, 2008-2012 . Infect Control Hosp Epidemiol. 2015 Nov;36(11):1298-304. doi: 10.1017/ice.2015.185. Epub 2015 Aug 27.

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Johnson NB, Hayes LD, Hoo EC, Ethier KA. CDC National Health Report: leading causes of morbidity and mortality and associated risk and protective factors – United States, 2005-2013 . Morb Mortal Wkly Rep Suppl. 2014 Oct 31;63(4):3-27.

Dantes R, Mu Y, Belflower R, Aragon D, Dumyati G, Harrison LH, Lessa FC, Lynfield R, Nadle J, Petit S, Ray SM, Schaffner W, Townes J, Fridkin S. Emerging Infections Program–Active Bacterial Core Surveillance MRSA Surveillance Investigators. National burden of invasive methicillin-resistant Staphylococcus aureus infections, United States, 2011 . JAMA Intern Med. 2013 Nov 25;173(21):1970-8. doi: 10.1001/jamainternmed.2013.10423.

Nguyen DB, Lessa FC, Belflower R, Mu Y, Wise M, Nadle J, Bamberg WM, Petit S, Ray SM, Harrison LH, Lynfield R, Dumyati G, Thompson J, Schaffner W, Patel PR; for the Active Bacterial Core surveillance (ABCs) MRSA Investigators of the Emerging Infections Program. Invasive methicillin-resistant Staphylococcus aureus infections among chronic dialysis patients in the United States, 2005-2011 . Clin Infect Dis. 2013 Nov;57(10):1393-400. doi: 10.1093/cid/cit546. Epub 2013 Aug 19.

Tosh PK, Bulens SN, Nadle J, Dumyati G, Lynfield R, Schaffner W, Ray S, Seema J, Fridkin SK, Sievert DM. Characterization of hospitalized community-onset Staphylococcus aureus lower respiratory tract infections among generally healthy persons 50 years of age or younger . Infect Dis Clin Prac. 2013 Nov;21(6):359-65.

Iwamoto M, Mu Y, Lynfield R, Bulens SN, Nadle J, Aragon D, Petit S, Ray SM, Harrison LH, Dumyati G, Townes JM, Schaffner W, Gorwitz RJ, Lessa FC. Trends in invasive methicillin-resistant Staphylococcus aureus infections . Pediatrics. 2013 Oct;132(4):e817-24. doi: 10.1542/peds.2013-1112. Epub 2013 Sep 23.

Duffy J, Dumyati G, Bulens S, Namburi S, Gellert A, Fridkin SK, Lessa FC. Community-onset invasive methicillin-resistant Staphylococcus aureus infections following hospital discharge . Am J Infect Control. 2013 Sep;41(9):782-6. doi: 10.1016/j.ajic.2012.10.020. Epub 2013 Feb 5.

Lessa FC, Mu Y, Ray SM, Dumyati G, Bulens S, Gorwitz RJ, Fosheim G, Devries A, Schaffner W, Nadle J, Gershman K, Fridkin SK for the Active Bacterial Core surveillance (ABCs) MRSA Investigators of the Emerging Infections Program. Impact of USA300 methicillin-resistant Staphylococcus aureus on clinical outcomes of patients with pneumonia or central line-associated bloodstream infections . Clin Infect Dis. 2012 Jul;55(2):232-41. doi: 10.1093/cid/cis408. Epub 2012 Apr 20.

Hadler JL, Petit S, Mandour M, Cartter ML. Trends in Invasive Infection with methicillin-resistant Staphylococcus aureus, Connecticut, 2001-2010 . Emerg Infect Dis. 2012 Jun;18(6):917-24. doi: 10.3201/eid1806.120182.

Bender JB, Waters KC, Nerby J, Olsen KE, Jawahir S. Methicillin-resistant Staphylococcus aureus (MRSA) isolated from pets living in households with MRSA-infected children . Clin Infect Dis. 2012 Feb 1;54(3):449-50. doi: 10.1093/cid/cir714. Epub 2011 Oct 31.

Nerby JM, Gorwitz R, Lesher L, Juni B, Jawahir S, Lynfield R, Harriman K. Risk factors for household transmission of community-associated methicillin-resistant Staphylococcus aureus . Pediatr Infect Dis J. 2011 Nov;30(11):927-32. doi: 10.1097/INF.0b013e31822256c3.

Satola SW, Lessa FC, Ray SM, Bulens SN, Lynfield R, Schaffner W, Dumyati G, Nadle J, Patel JB, Active Bacterial Core surveillance (ABCs) MRSA Investigators. Clinical and laboratory characteristics of invasive infections due to methicillin-resistant Staphylococcus aureus isolates demonstrating a vancomycin MIC of 2 micrograms per milliliter: lack of effect of heteroresistant vancomycin-intermediate S. aureus phenotype . J Clin Microbiol. 2011 Apr;49(4):1583-7. doi: 10.1128/JCM.01719-10. Epub 2011 Feb 16.

Satola SW, Farley MM, Anderson KF, Patel JB. Comparison of detection methods for heteroresistant vancomycin-intermediate Staphylococcus aureus, with the population analysis profile method as the reference method . J Clin Microbiol. 2011 Jan;49(1):177-83. doi: 10.1128/JCM.01128-10. Epub 2010 Nov 3.

DeVries AS, Lesher L, Schlievert PM, Rogers T, Villaume LG, Danila R, Lynfield R. Staphylococcal toxic shock syndrome 2000-2006: Epidemiology, clinical features, and molecular characteristics . PLoS One. 2011;6(8):e22997. doi: 10.1371/journal.pone.0022997. Epub 2011 Aug 10.

Como-Sabetti KJ, Harriman KH, Fridkin SK, Jawahir SL, Lynfield R. Risk factors for community-associated Staphylococcus aureus infections: results from parallel studies including methicillin-resistant and methicillin-sensitive S. aureus compared to uninfected controls . Epidemiol Infect. 2011 Mar;139(3):419-29. doi: 10.1017/S0950268810001111. Epub 2010 Jun 1.

Kempker RR, Farley MM, Ladson JL, Satola S, Ray SM. Association of methicillin-resistant Staphylococcus aureus (MRSA) USA300 genotype with mortality in MRSA bacteremia . J Infect. 2010 Nov;61(5):372-81. doi: 10.1016/j.jinf.2010.09.021. Epub 2010 Sep 22.

Lessa FC, Mu Y, Davies J, Murray M, Lillie M, Pearson A, Fridkin S for the Emerging Infections Program/Active Bacterial Core surveillance MRSA investigators and the Health Protection Agency Team. Comparison of incidence of bloodstream infection with methicillin-resistant Staphylococcus aureus between England and United States, 2006-2007 . Clin Infect Dis. 2010 Oct 15;51(8):925-8. doi: 10.1086/656414.

Shukla SK, Karow ME, Brady JM, Stemper ME, Kislow J, Moore N, Wroblewski K, Chyou PH, Warshauer DM, Reed KD, Lynfield R, Schwan WR. Virulence genes and genotypic associations in nasal carriage, community-associated methicillin-susceptible and methicillin-resistant USA400 Staphylococcus aureus isolates . J Clin Microbiol. 2010 Oct;48(10):3582-92. doi: 10.1128/JCM.00657-10. Epub 2010 Jul 28.

Kallen AJ, Mu Y, Bulens S, Reingold A, Petit S, Gershman K, Ray SM, Harrison LH, Lynfield R, Dumyati G, Townes JM, Schaffner W, Patel PR, Fridkin SK for the Active Bacterial Core surveillance (ABCs) MRSA Investigators of the Emerging Infections Program. Healthcare-associated invasive MRSA infections, 2005-2008 . JAMA. 2010 Aug 11;304(6):641-8. doi: 10.1001/jama.2010.1115.

Lucero CA, Hageman J, Zell ER, Bulens S, Nadle J, Petit S, Gershman K, Ray S, Harrison LH, Lynfield R, Dumyati G, Townes JM, Schaffner W, Fridkin SK for ABCs MRSA Investigators. Evaluating the potential public health impact of a Staphylococcus aureus vaccine through use of population-based surveillance for invasive methicillin-resistant S. aureus disease in the United States . Vaccine. 2009 Aug 13;27(37):5061-8. doi: 10.1016/j.vaccine.2009.06.055. Epub 2009 Jul 2.

Limbago B, Fosheim GE, Schoonover V, Crane CE, Nadle J, Petit S, Heltzel D, Ray SM, Harrison LH, Lynfield R, Dumyati G, Townes JM, Schaffner W, Mu Y, Fridkin SK, Active Bacterial Core surveillance MRSA Investigators. Characterization of methicillin-resistant Staphylococcus aureus isolates collected in 2005 and 2006 from patients with invasive disease: a population-based analysis . J Clin Microbiol. 2009 May;47(5):1344-51. doi: 10.1128/JCM.02264-08. Epub 2009 Mar 25.

Tenover FC, McAllister S, Fosheim G, McDougal LK, Carey RB, Limbago B, Lonsway D, Patel JB, Kuehnert MJ, Gorwitz R. Characterization of Staphylococcus aureus isolates from nasal cultures collected from individuals in the United States in 2001 to 2004 . J Clin Microbiol. 2008 Sep;46(9):2837-41. doi: 10.1128/JCM.00480-08. Epub 2008 Jul 16.

Buck JM, Harriman KH, Juni BA, Gall K, Boxrud DJ, Glennen A, Danila R, Lynfield R. No change in methicillin-resistant Staphylococcus aureus nasal colonization rates among Minnesota school children during 2 study periods . Infect Dis Clin Pract. 2008 May;16(3):163-5.

Klevens MR, Morrison MA, Nadle J, Petit S, Gershman K, Ray S, Harrison LH, Lynfield R, Dumyati G, Townes JM, Craig AS, Zell ER, Fosheim GE, McDougal LK, Carey RB, Fridkin SK for Active Bacterial Core surveillance (ABCs) MRSA Investigators. Invasive methicillin-resistant Staphylococcus aureus infections in the United States . JAMA. 2007 Oct 17;298(15):1763-71.

Klevens MR, Morrison MA, Fridkin SK, Reingold A, Petit S, Gershman K, Ray S, Harrison LH, Lynfield R, Dumyati R, Townes JM, Craig AS, Fosheim G, McDougal LK, Tenover FC, for ABCs/EIP. Community-associated methicillin-resistant Staphylococcus aureus and healthcare risk factors . Emerg Infec Dis. 2006 Dec;12(12):1991-3.

Buck JM, Como-Sabetti K, Harriman KH, Danila RN, Boxrud DJ, Glennen A, Lynfield R. Community-associated methicillin-resistant Staphylococcus aureus, Minnesota, 2000-2003 . Emerg Infect Dis. 2005 Oct;11(10):1532-8.

Fridkin SK, Hageman JC, Morrison M, Sanza LT, Como-Sabetti K, Jernigan JA, Harriman K, Harrison LH, Lynfield R, Farley MM for the Active Bacterial Core Surveillance Program of The Emerging Infections Program Network. Methicillin-resistant Staphylococcus aureus disease in three communities . N Engl J Med. 2005 Apr 7;352(14):1436-44.

Naimi TS, LeDell KH, Como-Sabetti K, Borchardt SM, Boxrud DJ, Etienne J, Johnson SK, Vandenesch F, Fridkin S, O’Boyle C, Danila RN, Lynfield R. Comparison of community- and health care-associated methicillin-resistant Staphylococcus aureus infection . JAMA. 2003 Dec 10;290(22):2976-84.

Morin C, Hadler JL. Population-based incidence and characteristics of community-onset Staphylococcus aureus infections with bacteremia in 4 metropolitan areas in Connecticut, 1998 . J Infect Dis. 2001 Oct 15;184(8):1029-34. Epub 2001 Sep 4.

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